There are a few routes to get your RN and you've just described them.
One is to get your LPN first and then your RN. Many people like to do that because it gets them working as a nurse quicker.
To get your RN you can also go straight to RN school either through an Associates Degree or a Bachelor's Degree. Both degrees allow you to take the test to become an RN.
If you are able and have time and can afford (or get loans like most of us do) to get your Bachelor's Degree that is the best way to go.
Good luck. This is a great site to ask those sorts of questions so if you have questions don't hesitate to ask.